Electric switch



Oct. 18,1932. A Q ROWLEY .1,882,674

ELECTRIC SWITCH Filed July 24. 19:50

Patented Oct. 18, 1932 UNITED STATES PATENTl oFFicE ARTHUR C. ROWLEY, OFPHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GLOBE AUTO- MATIC SPRINKLERCOMPANY,'OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIAELECTRIC SWITCH This invention relates toelectric switches, and moreYparticularly to a type of switch adapted for use in connection withfire-extinguishing and alarm apparatus.

A principalobject of the invention is to provide a switch of the statedcharacter which shall be simple in form and eiiicient and positive inoperation.

More specifically, an object of the invention is to provide a switch ofimproved design adapted for operative association with thermosensitivemeans whereby abnormal temperature conditions aecting the latter resultin a predetermined actuation of the switch mechanism.

Another object of the invention is to provide improvedmeans foreffecting a desired actuation of the switch mechanism underpredetermined conditions.

Still another object of the invention is to provide .an electric switchincluding latching means for normally retaining the switch in an openposition, together with novel and improved means for tripping the saidlatch to permit the switch to close.

The inventionv contemplates further the provision of aswitchincorporating a novel and highly desirable fluid control, as hereinafterfully described.

The invention further resides in certain novel mechanical and structuraldetails and features hereinafter setforth and illustrated in theattached'drawing, in which Figure 1 is a front elevational view of aswitch made in accordance with my inventionj the cover of the switchbeing` removed to render the interior working parts visible;

Fig. 2 is a section on the line 2-2, Fig. 1;

Fig. 3 is a view in perspective of one of the elements of the mechanism,and

Fig. 4 is a fragmentary sectional view on the line 4 4, Fig. 2.

With reference to the drawing, a device made in accordance with myinvention may comprise a housing 1 having a removable cover-plate 2.Within the housing is assembled an electric switch comprising in thepresent instancea pair of relatively fixed contact or terminal elments3, 3, these elements being mounted in the present instance upon aninsulating block 4 shown attached to the l I rearwall of the housing bymeans of screws 5. Binding posts G are provided whereby wires (notshown), entering the housing .through a bottom opening 7, may beconnect- `ed respectively to the contacts 3. The switch vmechanismfurther comprises a movable contact element in the form of a plate Sflexibly secured by means of a screw 9 and a spring 11, the latterconfined between the head of said screw and the outer face of the plate,to an linsulating member 12, this member being pivotally mounted upon arod 13 within the housing and being adapted to rock in such manner as tobring contact points 14 on the plate 8 into engagement, respectively,with the terminal elements 3, thereby elecn ,trically connecting theseterminal elements and closing the electric circuit of which the saidvterminals form a part. The plate 8 has at its upper end a lip or flange15 which projects inwardly into an aperture in the foi'- ward face ofthe insulator 12, and except for lthe restrictions imposed by this lip15, the

screw 9, and the spring 11, the plate is free to move with respect toits insulating support 12.

Secured to the upper end of the insulator 12, by means in the presentinstance of screws 16, is an arm 17 the forward upturned end' 18 ofwhich projects into an'aperture 19 in the cover-plate 2, while the rearend is piovided with an upwardly projecting flange 21. The arm 17 hasoperatively associated therewith a spring actuator consisting of aninverted hollow cylinder 22 containing a coiled spring 23 whichsurrounds a plunger 24 slidable in the cylinder, the spring beingconfined between the closed end of the cylinder 22 and the flanged headof the plunger l 24. The actuator itself is confined between a screwl 25extending through the upper wall of the housing 1 and the upper surfaceof the arm 17, the arrangement being such that the spring 23 exerts apressure tending to move the insulator 12 about the pivot rod 13 in suchmanner as to bring the contact plate 8 into engagement with theterminals 3, as previously set forth. Displacement of the yspringactuator 22-2324 from the confined Vao position is prevented byinterlocking connections between the bottom of the plunger 24 and thearm 17 and between the cylinder 22 and the screw 25, the said plungerand screw each having an attenuated extremity, which extremities seatwithin suitable recesses in the arm 17 and in the plunger 22respectively.

The contact element 8 normally is held out of engagement with theterminals 3 by a latch element 26 pivotally mounted upon a rod 27extending between lugs 28, 28, within the housing, this latch having ashouldered projection 29 which hooks over the upper edge of theupstanding flange 21 of the member 17. Another depending arm 31 ofthelatch 26 is engaged and releasably retained by one arm of a detent 32pivotally supported between the lugs 33, 33,which also support the rod13 upon which the insulator 12 is mounted'. The other arm 34 of thedetent 32 normally underlies a shoulder 35 on a depending bifurcatedlever, 36, this lever being pivotally mounted upon a pin 37 extendingbetween the lugs 28, 28. The lever has an extension 38 at the top towhich is attached a spring 39, this spring tending to retain the lowerdepending portion of the lever in an advanced position interlocking withthe detent 32, as described above and illustrated in the drawing.Retraction of the lever 36 inl a manner hereinafter set forth releasesthe detent 32 and the latch 26and permits the spring 23 to swing thepivoted insulator 12 into engagement with a stop 41 in the housing, thestop 41 being so positioned, however, as in no way to interfere withcontact between the elements 14 of the plate 8 and the terminal elements3. By reason of the flexible mounting of the plate 8, this member isself-adjustable in its contact with the terminals 3, insuring proper andintimate electrical connections.

Secured to the rear wall of the housing 1 are plates 42 and 43, theseplates being dished in their inner faces to. form an interior chamber 44which is intersected by a flexible disk or diaphragm 45 confined betweenthe edges of the plates, as illustrated in Fig. 2. Both of the plates 42and 43 are secured in the housing bymeans of a series of screws 46,theplates being thereby secured together upon the diaphragm 45 and to thehousing in a osition overlying and closing an opening 4i) in the rearwall of said housing. The plate 43 has a boss 48 projecting outwardlyinto the housing opening 47 ,and this boss is threaded for reception ofa hollow fixture 49 in which is secured, by means for example of solder51, one end of'a duct 52, which thus has communication through the saidfixture with the chamber 44. The duct 52 extends downwardly in thepresent instance through a channel 53 at therear of the housing 1, andthe lower end of the channel is threaded for connection of a conduit,not shown. Secured t0 the center of the diaphragm is a pin 54 whichprojects through the plate 42 and between the bifurcations of the lever36, and has at its extremity a head 55 overlapping the saidbifurcations. The arrangement is such that evacuation of the chamber 44through the duct 52 causes a deflection of the diaphragm 45 andretraction of the pin 54, and through this pin of the lever 36, thisresulting in a release of the detent 32 and of the associated elementsand a closing of the switch 3 8, all as previously set forth.

Following release of thc latching device and closing of the switch, asdescribed above, the mechanism may be reset by pressing upon the end 18of the arm 17, which when the switch is closed projects through theopening 19 in the cover-plate. The iiange 21 never clears the under sideof the latch 26, so that pressure applied to the end of the arm 17 willcause the flange 21 to move inwardly behind the retaining shoulder.Further pressure will bring the-flange against theforward side of thedepending arm 31 of the latch, and this arm will thus be made to reactwith the detent 32 to force the arm 34 of this member under the shoulder35 of the lever 36, the latter being displaced inwardly to an extentsufficient to permit the arm 34 to move under the shoulder. It will benoted by reference to Fig. 4 that the detent 32 is supported orjournaled on the inner ends of two pins 56, 56, which are threaded intothe lugs 33, and that the detent has in its mid section a recess 57 inwhich the lower end of the arm 31 of the latch 26 is confined, the arm31 thus being aorded the necessary bearing on the detent.

In practice, the duct 52 may be suitably connected with athermally-controlled evacuating device, such as that illustrated in mycopending application, Serial Number 314,-

511, whereby excessive temperatures at the point Vwhere this device isestablished results in an evacuation of the chamber 44 and release ofthe latching mechanism, as previously set forth, the switch therebyclosing an electric circuit` which may be connected to the releasedevice of a fire-extinguishing system, such for example as thatillustrated in my copending application Serial Number 460,511, or to analarm or to any other electrically-operated mechanism.

The herein described device is capable of considerable modiicationwithout departure from the invention. It may be desirable, for example,to actuate the diaphragm 45 to release the associated latch mechanism byincreasing the pressure at one side thereof instead of by evacuation, asdescribed above, although evacuation is considered desirable. Theinvention is applicable also to actuation of switch mechanism to open anelectric circuit, instead of to close the circuit as inI the illustratedembodiment.

I claim:

In a fluid-actuated electric switch, the combination with afluid-actuated member, of switch elements relatively movable intoalternative relative positions in which an electric circuit is closedand opened respectively, a system of latch levers in series arrangementoperatively connecting said fluid-actuated member With the switchelements for normally retaining the elements in one of said alternativepositions, and a spring tending to bring said elements into the other ofsaid alternative positions, said latch system comprising a pivotallymounted bell crank lever one arm of Whichis adapted to releasablyinterlock with one of said switch elements, a second pivoted leverhaving a recess for reception of another arm of said lirst-named lever,and a third pivoted lever constituting a detent for said recessed leverand retractible from an operative position by movement of saidfluid-actuated member under a relatively light fluid pressure.

ARTHUR C. ROWLEY.

